Question 1060660
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Can you please help me. I'm want to solve this system of equation using the substitution method. 
-3x+3y=4
-x+y=3
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<pre>
-3x + 3y = 4,   (1)
-x  +  y = 3    (2)

From (2), express y = 3+x and substitute this expression into equation (1) replacing y. You will get

-3x + 3(3+x) = 4.

Simplify:

-3x + 9 + 3x = 4.

9 = 4.


Absurd ?  Sure.  It means that the original system has no solutions.
It is <U>inconsistent</U>. 


One can see it immediately/instantly after seeing the original system.
Indeed, multiply the second equation by 3. 
You will get an equivalent equation

-3x + 3y = 9.   (2')

Now compare (2') with (1). They have identical left sides, but different right sides.
Such a system is <U>inconsistent</U>.
</pre>

For better understanding, see the lessons

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF = http://www.algebra.com/algebra/homework/coordinate/lessons/Solution-of-the-lin-system-of-two-eqns-by-the-Subst-method.lesson>Solution of the linear system of two equations in two unknowns by the Substitution method</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF =http://www.algebra.com/algebra/homework/coordinate/lessons/Solution-of-the-lin-syst-of-two-eqns-with-two-unknowns-using-det.lesson>Solution of the linear system of two equations in two unknowns using determinant</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF = http://www.algebra.com/algebra/homework/coordinate/lessons/Solution-of-the-lin-syst-of-two-eqns-with-two-unknowns-Elimination-method.lesson>Solution of the linear system of two equations in two unknowns by the Elimination method</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF =http://www.algebra.com/algebra/homework/coordinate/lessons/Geom-interpret-of-the-lin-system-of-two-eqns-with-two-unknowns.lesson>Geometric interpretation of the linear system of two equations in two unknowns</A> 

in this site.


Also, you have this free of charge online textbook in ALGEBRA-I in this site

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.


The referred lessons are the part of this online textbook under the topic "<U>Systems of two linear equations in two unknowns</U>".